Method for manufacturing carbon-sulfur composite, carbon-sulfur composite manufactured thereby, and electrochemical device including the same

Abstract

The present invention relates to a method for manufacturing a carbon-sulfur composite, a carbon-sulfur composite manufactured by the method, and an electrochemical device including the same. Since the carbon-sulfur composite manufactured by the carbon-sulfur composite manufacturing method of the present invention includes the hollow carbon ball having the inner hollow which is uniformly filled with sulfur, a sulfur content increases to increase a capacity characteristic increases. In addition, even though sulfur is changed into a liquid state during charge and discharge processes, an electrode structure is not destroyed to realize a stable lifetime characteristic.

1 . A method for manufacturing a carbon-sulfur composite, the method comprising:
 generating an organic silica fine particle;   mixing and hydrothermally reacting the organic silica fine particle with a carbon precursor to form a suspension;   after drying the suspension, thermally treating the suspension in an inert-gas atmosphere;   immersing the thermally treated particle in an etching solution to remove inner silica;   thermally treating the organic silica fine particle from which the inner silica is removed, thereby manufacturing a hollow carbon particle; and   impregnating sulfur into the hollow carbon particle.   
     
     
         2 . The method of  claim 1 , wherein generating the organic silica fine particle comprises:
 adding an organic silane and a basic catalyst into a solvent to carry out an organic silane condensation polymerization reaction.   
     
     
         3 . The method of  claim 2 , wherein the organic silane is selected from a group consisting of 3-mercaptopropyl trimethoxy silane (MPTMS), phenyl trimethoxy silane (PTMS), vinyl trimethoxy silane (VTMS), methyl trimethoxy silane (MTMS), 3-aminopropyl trimethoxy silane (APTMS), 3-glycidyloxylpropyl trimethoxy silane (GPTMS), (3-trimethoxysilyl)propylmethacrylate (TMSPMA), and 3-(trimethoxysilyl)propylisocyanate (TMSPI). 
     
     
         4 . The method of  claim 2 , wherein the solvent is selected from a group consisting of water, alcohol, and a mixture thereof. 
     
     
         5 . The method of  claim 2 , wherein the basic catalyst is selected from a group consisting of a compound containing an amino group and a hydroxyl group, an ammonia water solution, a sodium hydroxide water solution, an alkylamine water solution, and any mixture thereof. 
     
     
         6 . The method of  claim 1 , wherein the etching solution uses HF, a mixture solution of HF and NaOH, or a mixture solution of HF and KOH. 
     
     
         7 . The method of  claim 1 , wherein a ratio of the etching solution to 1 weight part of the carbon-sulfur composite is in a range of 0.1 weight part to 2.0 weight parts when the inner silica is etched. 
     
     
         8 . The method of  claim 1 , wherein the carbon precursor is selected from a group consisting of sucrose, glucose, and xylose. 
     
     
         9 . The method of  claim 1 , wherein impregnating the sulfur into the hollow carbon particle comprises:
 separately providing the hollow carbon particle and the sulfur in a reactor; and   filling an inside of the hollow carbon particle with the sulfur by temperature rising and thermal treatment under vacuum.   
     
     
         10 . The method of  claim 9 , wherein separately providing the hollow carbon particle and the sulfur in the reactor comprises:
 separately providing the hollow carbon particle and the sulfur in the reactor at a ratio of sulfur that is in a range of 50 weight parts to 300 weight parts per 100 weight parts of the hollow carbon particle.   
     
     
         11 . A carbon-sulfur composite manufactured by the method of  claim 1 . 
     
     
         12 . The carbon-sulfur composite of  claim 11 , wherein the carbon-sulfur composite includes an inner hollow, and
 wherein a weight ratio of sulfur disposed in the inner hollow is in a range of 50 weight parts to 60 weight parts per 100 weight parts of the carbon-sulfur composite.   
     
     
         13 . The carbon-sulfur composite of  claim 11 , wherein a diameter of the carbon-sulfur composite is in a range of 50 nm to 1 μm. 
     
     
         14 . The carbon-sulfur composite of  claim 11 , wherein the carbon-sulfur composite has two weight-loss temperatures in thermogravimetric analysis. 
     
     
         15 . An electrochemical device comprising the carbon-sulfur composite of  claim 11 . 
     
     
         16 . The electrochemical device of  claim 15 , wherein the electrochemical device is a lithium-sulfur battery that includes tetraethylene glycol dimethyl ether and lithium polysulfide that are used as an electrolyte.